Ultramar is an Eastern Canadian gas and home fuel retailer, with its head office located in Montreal, Quebec.

Ultramar operates gas stations and home fuel delivery in Ontario, Quebec, and Atlantic Canada.

[3] In 1994, Ultramar acquired Sergaz (founded in 1971 by André Ducharme) and Sunoco's Quebec gas stations.

The refinery in Lévis was renamed in honour of retired Ultramar Diamond Shamrock CEO Jean Gaulin in 2001.

Ultramar had 983 service stations, 87 truck stop facilities and 169,000 home heating oil customers.